function [spx, spy] = create_vslice_line ( x, y )
% CREATE_VSLICE_LINE:  compute the spline structures from the control points.
%
% USAGE:  [spx, spy] = draw_vslice_line ( cx, cy );
%
% PARAMETERS:
% Input:
%     x, y:  control points retrieved from ginput
% Output:
%     spx, spy:  spline structures defined by matlab routine "spline"
%
%
% Calls:
%    acquire_vslice_line
% Called by:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% $Name: rslice-0_9_2 $
% $Id: create_vslice_line.m,v 1.3 2005/07/07 15:19:33 jevans Exp $
% AUTHOR:  johnevans@acm.org
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


num_points = length(x);
	
if num_points < 2
	spx = []; spy = [];
else
	t = linspace ( 0, 1, num_points );
	t = t(:);

	spx = spline ( t, [0; x(:); 0] );
	spy = spline ( t, [0; y(:); 0] );
end

return

